Rules and Guidance for the Classification of Floating Docks

2020

Rules and Guidance for the Classification ofFloating Docks

KR

2020Rules for the Classification of

Floating Docks

Rules

2020Guidance Relating to the Rules for the Classification of

Floating Docks

Guidance

2020

Rules for the Classification of Floating Docks

RB-08-E KR

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APPLICATION OF "RULES FOR THE CLASSIFICATION OF FLOATING DOCKS"

1. Unless expressly specified otherwise, the requirements in the Rules apply to Floating Docks for which contracts for construction are signed on or after 1 July 2020.

2. The amendments to the Guidance for 2018 edition and their effective date are as fol-lows;

Effective Date 1 July 2020

CHAPTER 1 GENERAL

- 1102. has been amended.

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CONTENTS

CHAPTER 1 GENERAL ········································································································· 11100. General ····················································································································· 11101. Application ················································································································ 11102. Equivalency ·············································································································· 11103. Other regulations ···································································································· 11104. Towage certificate ·································································································· 11105. Cranes ······················································································································· 11200. Classification Registry ···························································································· 11201. Character of classification ····················································································· 11300. Definition ·················································································································· 21301. Length ······················································································································· 21302. Breadth ····················································································································· 21303. Depth ························································································································ 21304. Safety deck ·············································································································· 21305. Top deck ·················································································································· 21306. Pontoon ····················································································································· 21307. Rest ballast water ·································································································· 21308. Compensating ballast water ················································································· 21309. Lifting capacity ········································································································ 21310. Light displacement ································································································· 2

CHAPTER 2 CLASSIFICATION SURVEYS ··········································································· 32100. Classification Surveys during Construction ······················································· 32101. General ····················································································································· 32102. Plans and documents ···························································································· 32103. Survey of the work ································································································ 32104. Testing ······················································································································ 32200. Classification Survey after construction ····························································· 42201. Submission of plans and documents ································································ 42202. Survey ······················································································································· 42300. Periodical Survey and Occasional Survey ························································· 42301. General ····················································································································· 42302. Intermediate surveys ····························································································· 42303. Special survey ········································································································· 52304. Damage and lteration ···························································································· 52400. Cooperation for the survey ················································································ 6

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CHAPTER 3 GENERAL ARRANGEMENT ············································································ 73100. Safety Deck ············································································································· 73200. Top Deck ·················································································································· 73300. Ventilation and Access ·························································································· 73400. Cofferdam ··············································································································· 7

CHAPTER 4 FREEBOARD AND STABILITY ······································································· 94100. Freeboard ················································································································· 94101. Freeboard to top deck ·························································································· 94102. Freeboard to pontoon deck ················································································· 94103. Freeboard in unsheltered waters ········································································ 94200. Stability 【See Guidance】 ····················································································· 94201. General ····················································································································· 94202. Metacentric height, ······························································································ 94203. Statical stability diagram ······················································································· 94204. Wind heeling moment ·························································································· 9

CHAPTER 5 HULL STRUCTURE ························································································ 115100. General ··················································································································· 115101. Material ··················································································································· 115102. Welding ·················································································································· 115103. Corrosion protection ····························································································· 115104. General construction ···························································································· 115200. Longitudinal Strength ··························································································· 115201. Longitudinal strength ··························································································· 115202. Towing condition ·································································································· 125203. Ship weight curve ································································································ 125204. Allowable stresses ······························································································· 125205. Section modulus ··································································································· 125206. Approximate formula of required section modulus ······································ 125207. Operation manual ································································································· 125208. Deflection control ································································································· 125300. Transverse Strength ····························································································· 125301. Loading condition ································································································· 125302. Allowable stress ··································································································· 135303. Approximate formula ··························································································· 135400. Structural Detail and Local Strength ································································ 135401. Structural arrangement ························································································ 135402. Buckling ·················································································································· 135403. Tank and shell plates ·························································································· 135404. Tank stiffener and frame ··················································································· 145405. Girder, web frame etc. ······················································································· 145406. Cross tie ················································································································· 155407. Maximum differential head ················································································ 15

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5408. Top deck ················································································································ 155409. Safety deck ·········································································································· 165410. Non-water tight structures ················································································ 175411. Keel block and supporting structure ································································ 175412. Platforms ················································································································ 175413. Swing bridge ········································································································· 17

CHAPTER 6 MACHINERY AND INSTRUMENTATION ··················································· 196100. Machinery ··············································································································· 196101. Machinery ············································································································· 196102. Piping system ······································································································· 196103. Electrical equipment ···························································································· 196200. Indicator system ··································································································· 19

CHAPTER 7 FIRE PROTECTION AND EXTINGUISHING ················································· 217100. Genera1 ·················································································································· 217200. Fire Protection ······································································································· 217201. Accommodation ···································································································· 217202. Machinery space ··································································································· 217203. Paints ······················································································································ 217300 Fire-Extinguishing ·································································································· 217301. Piping system for fire-extinguishing ······························································· 217302. Hydrant, hose and nozzle ·················································································· 217303. International shore connection ·········································································· 217304. Portable extinguisher ··························································································· 227305. Fire smothering gas system ·············································································· 22

Ch 1 General Ch 1

Rules for the Classification of Floating Docks 2020 1

CHAPTER 1 GENERAL

1100. General

1101. Application1. This Rules applies to survey and construction of floating docks which intend to be registered or

which registered with classification.

2. The Rules are made for on the conditions that floating docks will be properly loaded and handled in sheltered waters; they do not provide for special distributions or concentrations of loading. The Society may also require additional strengthening to be fitted in any floating dock which in their opinion, may be subjected to severe stresses due to particular features in her design or when it is desired to make provision for exceptional loaded or ballasted conditions. In these cases particulars and relevant data are to be submitted for consideration.

3. The relevant parts of the Rules for the Classification of Steel Ships (hereinafter referred to as「the Rules」) apply to essential constructions, machinery and equipment not specified in these Rules, as may be required.

1102. EquivalencyThe equivalence of alternative and novel features which deviate from or are not directly applicable to the Rules is to be in accordance with Pt 1, Ch 1 of the Rules for the Classification of Steel Ships. (2020)

1103. Other regulationsThese Rules specify the requirements for the Classification of floating docks. Therefore, the atten-tion of owners, builders, and designers is directed to the regulations of national or local govern-ments, or other organizations which may contain safety, health, or other standards applicable to the floating dock.

1104. Towage certificateWhere the Society's towage certificate is requested by a builder/owner to enable a dock to be tow-ed at sea special consideration may be required to be given to the strength, freeboard and stability, and other items as considered necessary.

1105. CranesWhen the assignment of safe working load of cranes is requested by the builders or the owners, the Society will assign the safe working load in accordance with Pt 9, Ch 2 of the Rules for the Classification of Steel Ships.

1200. Classification Registry

1201. Character of classification1. The class notations assigned to the floating dock classed with the Society are to be in accordance

with the requirements specified in Pt 1, Ch 1, 201. of the Rules. However, the notation "Floating Structure" shall be assigned as a ship type notation.

2. For barge equipped with skid (launching) arrangements, the notation "Launching Skid Barge" shall be assigned as a ship type notation.

Ch 1 General Ch 1

2 Rules for the Classification of Floating Docks 2020

1300. Definition

1301. LengthThe length () is the distance, in meters, measured on water line when supporting a ship whose displacement is the lifting capacity between the aft end and the fore end of the bulkheads of the floating structures of the dock.

1302. BreadthThe breadth ( ) is the moulded breadth in meters measured at the greatest horizontal distance be-tween the inner surfaces of the outer side plating of wing walls.

1303. DepthThe Depth () is the vertical distance in meters measured at the centerline from the inner surface of the bottom plating to the inner surface of the top deck plating.

1304. Safety deckThe safety deck is a watertight deck extending over the length of the wing walls and located below the top deck.

1305. Top deckThe top deck is the deck extending over the length of the wing walls to form the top of the wing walls.

1306. PontoonThe pontoon is the structure that extends between and under the wing walls to form the bottom of the dock.

1307. Rest ballast waterThe rest ballast water is ballast water which can not be discharged by pumps from ballast compartments.

1308. Compensating ballast waterThe compensating ballast water is ballast water for reduction of stresses and deflections in the dock structures and for adjustment of the trim and heel of the dock.

1309. Lifting capacityThe lifting capacity () is the displacement of the heaviest ship it is intended that the dock shall lift in normal service.

1310. Light displacementThe light displacement of the dock is its complete weight including all machinery, cranes, equip-ment, full supply of consumables for operation of the dock (fuel oil, fresh water etc.), compensating ballast water (if necessary) and rest ballast water.

Ch 2 Classification Surveys Ch 2


CHAPTER 2 CLASSIFICATION SURVEYS

2100. Classification Surveys during Construction

2101. General1. In the Classification Survey during Construction, the hull structures, hull equipment, machinery, fire

protection and detection, fire extinction, electrical installation, stability and load lines are to be ex-amined in order to ascertain that they meet the relevant requirements of the Rules.

2. New installation of materials which contain asbestos is to be prohibited.

2102. Plans and documentsWhen a floating dock is intended to be classed with the Society, plans and documents showing the scantlings, arrangements and details of the principal parts of the structure, and relevant data are to be submitted for review or approval. Plans for approval are generally to be submitted in triplicate. In general, these plans and documents are to include the following (1) and (2) where applicable.(1) Plans for approval

(a) General arrangement plan(b) Transverse section scantlings at mid-length of dock(c) Structural plans of the wing walls and pontoons(d) Structural plans of the decks and bulkheads(e) Pumping arrangements(f) Machinery and electrical plans(g) Piping systems (diagram)(h) Fire extinguishing arrangements(i) Particulars of indicator systems for tank water level and drafts(j) Particulars of deflection indicating system

(2) Information(a) Specifications(b) Stability calculations and hydrostatic curves(c) Calculations and data for longitudinal, transverse and local strength(d) Operating manual including ballasting manual(e) Tank arrangements showing also maximum service heads and heights of overflows and air

pipes and where used in design, data showing the maxi-mum differential service head(f) Data relating to overall load due to crane including hook load and arrangement if cranes are

installed(g) Coating specifications(h) Testing schemes

2103. Survey of the workFrom the commencement of the work until the completion of the dock, the Surveys during con-struction are to examine the materials, workmanship and arrangements.

2104. TestingIn the classification surveys during construction, the following tests are to be carried out.(1) Tank testing

All tanks including those used for void tanks and cofferdams are to be separately tested by a head of water to the highest point to which the liquid will rise in service. Where the scantlings of a tank boundary are based on the maximum differential head in service, care is to be taken to ensure test heads do not exceed the design differential head. On submission of a1l necessary detail, air testing or hose testing may be considered as an alternative to the foregoing.

(2) Completion trialsOn the completion of the dock, trials are to be carried out to ascertain following :(a) The freeboard to top deck with the dock flooded.(b) The light displacement and the lifting capacity of the dock corresponding to the minimum



freeboard.(c) The position of the centre of gravity by an inclining test. Where it is difficult to calculate an

accurate centre of gravity by inclining test, the lightweight displacement shall be obtained through lightweight survey and centre of gravity shall be determined by calculation.

(d) Any built-in permanent deflection in the initial condition. The initial condition is a condition that all tanks for consumables (fresh water, fuel oil etc.) are completely filled, but all other tanks are empty, only rest ballast water remaining in the ballast tanks. The travelling cranes may be parked in positions giving equal draughts forward and aft.

(e) Correct calibration of deflection meters by simulating the most severe intended loading con-dition as far as practicable.

(3) General systemsThe machinery pumps, piping remote control/automatic control, instrumentation and fire-ex-tinguishing system are to be tested at the makers in accordance with the Rules for the Classification of Steel Ships as applicable. The Society may, however, omit the surveys or in-spection in the presence of the Surveyor at the makers, subject to submission of the maker's certificate and satisfactory performance witnessed by the Surveyor after installation. All machinery and systems relating to the classification of the dock are to be functionally tested after in-stallation in the presence of the Surveyor.

(4) Electrical equipmentThe following tests and inspections are to be carried out for electrical equipment after installation on the docks.(a) Insulation resistance test(b) Operation test of the essential electrical equipment(c) Other tests and inspections as considered necessary by the Society.

2200. Classification Survey after construction

2201. Submission of plans and documentsPlans showing the main scantlings and arrangements of the actual dock and documents specified in 2101. are to be submitted for approval. Records and reports relating to the construction of the dock should be submitted as may be required by the Society.

2202. SurveyIn all cases the full requirements of 2303. are to be carried out. During the survey, the Surveyors are to satisfy themselves regarding the workmanship and verify the approved scantlings and arrangements. For this purpose, and in order to ascertain the amount of any deterioration, parts of the structure will be required to be drilled as necessary, or alternatively to be measured by using appropriate methods to determine the actual thickness. However, docks of recent construction wi1l receive special consideration.

2300. Periodical Survey and Occasional Survey

2301. General1. To retain its class with the Society, a dock in normal service is to be subjected to periodical sur-

veys and survey of alternations, damages and repairs in accordance with the provisions in the fol-lowing 2302. to 2304.

2. The requirements of the Rules for the Classification of Steel Ships also apply as may be relevant to docks, unless otherwise specified in 2300. of this chapter.

2302. Intermediate surveys1. Intermediate Surveys are to be carried out within 3 months before or after the second or the third

anniversary date from the completion date of the initial classification Survey or of the previous Special Survey.



2. At each Intermediate Survey the following parts are to be examined and placed in good condition.(1) Pontoon, safety and top decks, wing wall plating above the light waterline, keel and side blocks

and their foundations.(2) Vents and overflow pipes, air pipes extending below decks to form air cushions and overboard

scuppers.(3) Companionways, ladders, and handrails and other means of protection that might be provided for

access to all spaces.(4) Deflection indicating system(5) Arrangement of fire protection and extinguishing.(6) Machinery, pumps and other equipment.

3. The boilers(if any) are to be examined at each intermediate Survey in accordance with the relevant of the Rules for the Classification of Steel Ships.

2303. Special survey1. The first Special Survey is to be completed within 5 years from the date of initial classification

Survey and thereafter within 5 years from the credited date of the previous Special Survey.

2. At each Special Survey, the compliance with all Intermediate Survey requirements and the following requirements are to be examined.(1) Condition of means of protection to openings.(2) Pontoon and wing wall thanks are to be cleaned examined internally, and water tested to the

satisfaction of the Surveyor. At the discretion of the Surveyor, fuel oil tanks forming part of the main structure need not be examined internally until the dock is more than 15 years old.

(3) Spaces above safety deck are to be examined internally, removing linings, etc. where necessary for inspection. Air pipes extending below deck to form air cushions are also to be examined.

(4) Where the surface of plating is covered with cement, composition, or wood sheathing, the cov-ering is to be removed as may be required for examination of the plating.

(5) The thickness of any part of the structure where wastage is evident may be required by the Surveyor to be determined by an approved method. Where necessary the structure is to be renewed.

(6) The shell plating below the light waterline is to be examined.3. At the Special Survey after the dock is 20 years old, and at 10 years intervals thereafter, in addition

to the requirements of the preceeding 2, the thicknesses of the structure are to be determined by an approved method to assess the general condition. Two belts of gauging are to be made within the 0.4 mid-length of the dock.

4. Survey of the outer bottom below the light waterline is may be carried out by some combination of:(1) Ultrasonic measurement of plate thickness.(2) Heeling of the dock for partial examination of the bottom.(3) Underwater photography.(4) Underwater television.(5) Examination by diver.

5. For the extension of intervals of the examination below the waterline, special consideration may be given by the Society taking into account the condition of the dock, painting method and corrosion protection.

6. Surveys of boilers are to be in accordance with the requirements of Pt 1, Ch 2, Sec 8 of the Rules for the Classification of Steel Ships.

Surveys of machinery, piping systems and electrical equipment are to be in accordance with the relevant requirements of Pt 1, Ch 2, Sec 5 of the Rules for the Classification of Steel Ships as far as applicable.

2304. Damage and lterationDamage or alteration to structure, machinery or equipment, which affects or may affect classi-fication, is to be submitted by the owners or their representatives for examination by the Surveyor. This examination is to be requested by the owners or their representatives.



2400. Cooperation for the survey All such preparations as required for the survey to be carried out as well as those which may be required by the Surveyor as necessary in accordance with the requirements in the Rules are to be made by the applicant of the survey.The survey may be suspended where necessary preparations have not been made or any appro-priate attendant is not present.

Ch 3 General Arrangement Ch 3


CHAPTER 3 GENERAL ARRANGEMENT

3100. Safety DeckA safety deck is to be fitted at such a height below the top deck that when all tanks below the safety deck are flooded but with no load on the keel blocks, there is a reasonable freeboard from the top deck to the waterline. Alternative arrangements to fitting a safety deck, such as the provi-sion of an air cushion, will be given special consideration. Special consideration will also be given to the need for a safety deck in relation to the depth of water in which the deck operates.

3200. Top DeckThe dock is to be provided with a weathertight top deck, weathertight in this case meaning the ability to exclude water other than that due to rainfall in way of necessary access openings.

3300. Ventilation and AccessAll tanks are to have vent or overflow pipes that terminate well above the water line at the max-imum draught when the dock is submerged. All compartments are to be provided with manholes for access and openings are to be arranged to provided adequate ventilation and access to all parts of the structure.

3400. Cofferdam Compartments carrying oil are to be separated by cofferdams from those carrying fresh or feed water.

Ch 4 Freeboard and Stability Ch 4


CHAPTER 4 FREEBOARD AND STABILITY

4100. Freeboard

4101. Freeboard to top deckWhen the dock is submerged to its maximum draught, the freeboard to the top deck is generally not to be less than l.0 m.

4102. Freeboard to pontoon deckThe freeboard to the pontoon deck with the dock in its final working condition with a ship corre-sponding to the lifting capacity of the dock on the blocks is not to be less than 300 mm at the centerline and not less than 75 mm at the inner wing walls. The dock cranes may be positioned so as to produce no trim.

4103. Freeboard in unsheltered watersIf the dock's port of operation is not sheltered against waves, greater freeboard than given by 4101. and 4102. may be required.

4200. Stability 【See Guidance】

4201. GeneralThe requirements for stability specified in 4202., 4203. and 4204. below apply to the docks operat-ing in sheltered waters and special consideration will be given to the docks operating in areas other than sheltered waters.

4202. Metacentric height, In general, the initial metacentric height is not to be less than 1.0 m in any condition of loading as referred to in (1), (2) and (3) below. For transient conditions of short duration, however, a smaller metacentric height may be accepted upon special consideration.(1) Dock fully submerged to the minimum freeboard to the top deck.(2) Dock with pontoon immersed to just below top of keel blocks, with the most unfavourable typi-

cal ship supported by the blocks, and restoring water-plane for the combination dock/ship pro-vided on1y by the wing walls of the dock.

(3) Dock in final working condition with typical ships on the blocks, including the most unfavourable ship.

4203. Statical stability diagramThe statical stability diagram including wind heeling moment curve is to be submitted for the design condition of 4202. (3).In general, the point of intersection between the statical stability curve and the wind heeling mo-ment curve is un-der no circumstance to exceed the angle where any part of the pontoon deck submerges.

4204. Wind heeling momentThe wind heeling moment may be calculated from the following formula.

×× (t-m)

where: : the longitudinal projected area of the exposed surface considered at every stage of



inclining exposed areas of docked ship (m2).

∆ (m)

∆ : Vertical distance from the center of to the water line of the dock (m). : draught of the dock (m).

: wind velocity (m/sec), the wind velocity is not to be than 25 m/sec in genera1. However, the values of the wind velocity will depend on the service location and the mode of operation of the dock, and may be considered more precisely in each case.

Ch 5 Hull Structure Ch 5


CHAPTER 5 HULL STRUCTURE

5100. General

5101. Material1. The main structural members in this chapter are to be of the hull structural rolled steels specified in

"Rules for the Classification of Steel Ships" or equivalent.

2. Grade A steels specified in "Rules for Classification of Steel Ships" may be used for the main the main structural members of the dock. Grade D steels will, however, be required for the main struc-tural members such as the deck plates, shell plates and their girders within 0.4 amid-length, where the thickness exceeds 30 mm.

3. If the dock is to be operated in a site with air temperatures regularly below 0℃ in the winter sea-son, the notch toughness of the steels will be given special consideration.

5102. WeldingWelding and we1d connections are to comply with the requirements of "Rules for the Classification of Steel Ships", as far as applicable to the docks. Alternatively, welding may be in accordance with another recognized standard provided all related requirements of the standard are also complied with.

5103. Corrosion protectionAll external and internal surfaces of the hull structures except in oil tanks are to be protected against corrosion by paint of suitable composition or other effective means. Where special pro-tective coatings are applied to the external and internal surfaces, or other specially, effective meth-ods of corrosion control are adopted, reductions in scantlings will be specially considered.

5104. General construction1. The requirements in this chapter apply to the steel docks of the following types :

(1) Caisson type; dock in which the bottom pontoon and both dock wings are continuous and inseparable.

(2) Sectional pontoon type; dock in which the dock wings are continuous and the bottom consists of individual noncontinuous pontoons. The pontoons are permanently or detachably connected to the dock wings.

2. To avoid the excessive stress concentration, the structural members of the dock are to be con-tinuous as far as possible.

5200. Longitudinal Strength

5201. Longitudinal strengthThe longitudinal strength of the dock is to be calculated for the most severe expected docking and transient loading conditions during normal operations. Such condition may be generally assumed that a ship having a weight equal to the maximum lifting capacity of the dock and the shortest ship's length expected is supported on the keel blocks, the center of the ship's length being positioned at the mid-length of the dock, and the freeboard at the pontoon deck is as described in 4102. The level of water ballast is to be constant over the length( ). The level of compensating ballast water may, however, be determined with the normal operation manual where it is intended that normal operation of the dock is to be by differential ballast conditions by special agreement with the Society.



5202. Towing conditionSpecial consideration will be given to the longitudinal strength where it is intended to tow the dock in unprotected waters, including particulars of the season and the duration and area of the towing operation.

5203. Ship weight curveThe weight curve of the ship is to be taken as a rectangle with a superimposed parabola of half the area of the rectangle, the length of each area being .

5204. Allowable stressesFor the loading conditions defined in 5201. the longitudinal bending stresses are not to exceed 142N/mm2 and the shear stresses are not to exceed 98 N/mm2.

5205. Section modulusWhen calculating the section modulus of the hull structure, the sectional area of all effective con-tinuous longitudinal strength members are to be included. The section modulus of the hull structure at its mid-length is to be maintained within 0.4 a mid-length of the dock, unless a1arger ex-tension or special strengthening is necessitated by the bending moment curve.

5206. Approximate formula of required section modulusNotwithstanding the requirements of 5201., 5203. and 5204. the section modulus required for the hul1 structure may be generally determined from the formula where the lifting capacity of the dock is not exceeds 40,000 tons.

(cm2)

: the maximum lifting capacity in tons

5207. Operation manualInformation on the loading conditions for the longitudinal strength is to be contained in the operation manual. Where governing bending moments and/or shear forces may occur at less than the max-imum lifting capacity, such conditions are to be investigated, and contained in the operation manual.

5208. Deflection controlThe maximum allowable deflection of the dock is to be submitted for approval. This deflection is not to exceed that corresponding to a stress of 142 N/mm2 when lifting the ship defined in 5201. As for deflection monitoring measures, see 6200.

5300. Transverse Strength

5301. Loading conditionThe transverse strength of the dock is to be calculated for the most severe expected docking and transient conditions during normal operations, and is to be examined at least for the conditions as follows;(1) The docked ship conditions : as described in 5201. It is assumed that the docked ship mally is

supported by the keel blocks only.(2) The transient condition : the dock emerging out of water with a typical ship fully supported on

the blocks and the pontoon deck subjected to a waterhead just below top of docking blocks, with corresponding ballast water in the tanks.



5302. Allowable stressUnder the loading conditions in 5301. the compressive or tensile stresses in transverse members are not to exceed 170 N/mm2. The shear stresses in the transverse members are not to exceed 98N/mm2.

5303. Approximate formulaWhere the maximum lifting capacity of the dock does not exceed 40,000 tons, calculations of the transverse strength defined in 5301. and 5302. may be omitted if the thickness of the top and bot-tom plates of the pontoon is not less than that given below :(1) Caisson type; obtained from the following formula.

(mm)

(2) Sectional pontoon type; given by the above(1) or obtained from the following formula, whichever is greater ;

× (mm)

where: : the maximum lifting capacity in tons : length of the sectional pontoon measured alongside the center line of the dock

in meters : depth of the pontoon at the center in meters

5400. Structural Detail and Local Strength

5401. Structural arrangementA centerline girder or longitudinal member is to provide adequate support for the keel blocks. Side girders or transverse members are to be arranged to support the side blocks.

5402. BucklingThe structural panels and members of the hull structures are to be adequately stiffened to vent buckling.

5403. Tank and shell platesThe thickness of the tank and shell plates is not to be less than obtained from the following formula. The minimum thickness is, however, to be 6.5 mm for the tank plates and 7 mm for the shell plates.

(mm)

where: : spacing of stiffeners, frames etc., in meters : 2.5 m or the followings, whichever is greater ;for tanks ;

vertical distance measured from the lower edge of plate to the mid-point of the distance between the top of tanks and the top of overflow pipes in meters. As an alternative the maximum differential head defined in 5407. may be used for the ballast tanks.



for cofferdams and void spaces; vertical distance measured from lower edge of plate to the maximum immersion water line in meters.

5404. Tank stiffener and frameThe section modulus of tank stiffeners and frames is not to be less than obtained from the follow-ing formula;

(cm3)

where: : spacing of stiffeners, frames etc. in meters : span of stiffeners, frames etc. in meters : 2.5 m or the followings, which ever is greater;for tanks;

vertical distance measured from the mid-point of for vertical stiffeners of for horizontal stiffeners to the midpoint of the distance between the top of tanks and the top of overflow pipes in meters. As an alternative, the maximum differential head defined in 5407. may be used for the ballast tanks.

for cofferdams and void spaces; vertical distance measured from the midpoint of for vertical frames etc. or for longitudinal frames etc. to the maximum immersion water line in meters.

: Coefficient given in Table 5.1, according to the type of end connections

One end of stiffenersThe other end of stiffeners

Connection by brackets

Lug-connection orsupported by girders Snip

Connection by brackets 0.70 0.85 1.30

Lug-connection orsupported by girders 0.85 1.00 1.50

Snip 1.30 1.50 1.50

Table 5.1 Values of

5405. Girder, web frame etc.1. The section modulus of the girders is not to be less than obtained from the following formula;

(cm3)

where: : breadth of the area supported by the girders in meters : span of the girders in meters : 2.5 m or the followings, which ever is greaterfor tanks;

vertical distance measured from the mid-point of for vertical girders etc. or for



horizontal girders etc. to the mid-point of the distance between the top of tanks and the top of overflow pipes in meters. As an alternative, the maximum differ-ential head defined, in 5407. may be used for ballast tanks.

for void spaces, cofferdams;vertical distance measured from the mid-point of for vertical web frames etc. or for horizontal web frames etc. to the maximum immersion water line in meters.

2. Thickness of girders is not to be less than obtained from the following formula.

(mm)

where: : stiffener space or depth of girders, whichever is less in meters.

5406. Cross tieThe sectional area of cross ties, where fitted between the stiffeners, frames, girders, web frames etc. is not to be less than obtained from the following formula.

(cm3)

where: : space of the stiffeners etc. supported by the cross tie in meters: : distance between the mid-point of two adjacent spans of stiffeners etc. supported

by the cross tie in meters. : the maximum head in meters to be determined in accordance with the require-

ments of 5404. or 5405. as applicable.

5407. Maximum differential headWhere the maximum differential head is used for the design basis of the ballast tanks, hydrostatic data is to be submitted for approval to show the differential head based on the highest levels to which water will rise on each side of the structure in service. The differential head on the design is to be determined with a suitable margin to an actual differential head in service. Necessary data on operating the dock within such design limits are to be included in the operating manual.

5408. Top deck1. Thickness of the top deck plates is not to be less than obtained from the following formula or 7

mm; whichever is greater.

(mm)

where: : beam space (m)

2. Section modulus of the top deck beam is not to be less than obtained from the following formula.

(cm3)

where:



: 14.5 for longitudinal beam within 0.4 amid-length, 5.4 for transverse beam and longitudinal beam at the fore and aft end.For longitudinal beam other than the aforesaid, may be gradually from 14.5 to 5.4.

: space of beam in meters : span of beam in meters

3. Section modulus of the transverse girder of the top deck is not to be less than obtained from the following formula.

(cm3)

where: : breadth of the area supported by the girders in meters : span of girder in meters

5409. Safety deck 1. Scantlings of the safety deck as constructed as the tanks are to be in accordance with the require-

ments defined in 5403., 5404. and 5405.2. Scantling of the safety deck as constructed as other than the tanks are to be as follows;

(1) Thickness of the deck plates is not to be less than 6.5 mm or obtained from the following for-mula, whichever is greater.

(mm)

where: : beam space in meters : deck loads in t/m2

(2) Section modulus of the deck beam is not to be less than obtained from the following formula.

(cm3)

where: : beam space in meters : deck loads in t/m2

: span of beam in meters(3) Section modulus of the deck girders is not to be less than obtained from the following formula.

(cm3)

where: : breadth of the area supported by the girders in meters : span of the girder in meters : deck load in t/m2



5410. Non-water tight structuresThe thickness of the web plates of the non-water tight structures such as the center girder, side girders and solid floors of the pontoon, and the non-water tight bulkheads, is not to be less than obtained from the following formula in general.

(mm)

where: : space of stiffeners in meters

5411. Keel block and supporting structureThe keel blocks and their supporting structures are to be generally designed to the following loads;

(t/m)

where: : loads to the keel blocks and supporting structures over the whole length of the

dock. : the maximum lifting capacity of the dock in tons.

5412. PlatformsThe minimum load on the platforms of dock ends is to be 5.88 kN/mm2, the factor of safety being not less than 4.

5413. Swing bridgeThe minimum load on the swing bridge at dock ends is to be 3.92 kN/mm2, the factor of safety being not less than 4.

Ch 6 Machinery and Instrumentation Ch 6


CHAPTER 6 MACHINERY AND INSTRUMENTATION

6100. Machinery

6101. Machinery The pressure vessels other than those belonging to Group 3 and essential machinery such as gen-erator driving and auxiliary machinery which are necessary for operations of the docks, are generally to be in accordance with the relevant provisions of the Rules for the Classification of Steel Ships.

6102. Piping system1. The piping systems are generally to be in accordance with Pt. 6 of the Rules for the Classification

of Steel Ships as far as applicable.

2. The dock is to have at least two water ballast pumps driven by each independent power. The ar-rangements for de-ballasting are to be such that in case of failure to the one pump an alternative pumping is available for each ballast tank.

6103. Electrical equipment1. Electrical equipment to be installed in the manner of minimizing the risks due to electrical cause

such as electric shocks, fires etc. on reference to the requirements of the Rules for the Classification of Steel Ships.

2. Electrical machinery and cables are to be those conformed to an applicable standards accepted by the Society, and suitable to be used safely and effectively under the conditions of the environment where they are installed.

3. Electric circuits are to be protected against accidental over currents including short circuit. These protecting devices are to be capable of breaking a fault circuit, eliminating the expansion of the faults and the hazards of fire and securing to serve electric power to essential driving sources, lights, internal communications and alarm devices.

4. Supply voltage (2018) In general, the voltage for the electric power supply to the dock is not to exceed 15 kV. Higher

voltages will be subject to special consideration.

5. Switchboard (2018)(1) Switchboard for shore side power supply is to be of the metal enclosed and dead-front type.

The following instruments are to be provided for each voltage level.· Voltmeter· Ammeter· Ground fault indication

(2) Switchboard is to be braced for maximum available fault current, and circuit breakers and fuses are to be capable of interrupting maximum fault current at their point of application. Fault cur-rent studies are to be submitted for approval and are to include determination of available feeder source current at the service disconnect switch.

6200. Indicator systemDeflection meters or acceptable alternatives, tank level, draught, and trim indicators are to be pro-vided to enable the operation of the dock to be proper1y controlled.

Ch 7 Fire Protection and Extinguishing Ch 7


CHAPTER 7 FIRE PROTECTION AND EXTINGUISHING

7100. Genera1The requirements of this Chapter apply to the minimum fire protection and extinction for the docks and do not cover equipment fitted for fighting fires that may occur on ships in the dock. Attention should also be given to any relevant statutory requirements of the National Authority of the country in which the dock is to operate. Compliance with such statutory requirements may, at the discretion of the Society, be accepted as meeting the requirements of this Chapter.

7200. Fire Protection

7201. AccommodationAccommodation, control station and service spaces are to be arranged so that the risk of fire will be reduced to a minimum. Deck houses are to be of steel or equivalent materials. Deck coverings on the decks forming the crown of machinery spaces are to be of a type which will not readily ignite.

7202. Machinery spaceBoundary walls of the machinery spaces and interior stairways below the top deck to be of steel or equivalent materials.

7203. PaintsIn accommodation, control station, service and machinery spaces, paints, varnished and similar prep-arations having a nitrocellulose or other highly inflammable bases are not to be used.

7300 Fire-Extinguishing

7301. Piping system for fire-extinguishingThe fire pumps, associated piping and fire main are to be so designed that a minimum pressure can be maintained sufficient to produce at least 12 m jet throw through adjacent nozzles of sizes required by 7302. A fire main is to be provided on each dock wing. Two separate means of water supply are to be provided for the fire main. At least, one mean of water supply is to be of an ad-equate shoreside supply or an independent driven emergency pump is to be provided with the dock.

7302. Hydrant, hose and nozzle1. The number and position of the hydrants are to be such that at least two jets of water not ema-

nating from the same hydrant, one of which is to be from a single length of hose, may reach any part of the dock except the water ballast tanks under any operating conditions.

2. In spaces containing machinery with a total power of 1,000 PS and over, two hydrants are to be provided, and in spaces where the total power of the machinery is less than 1,000 PS, one hydrant will be accepted. Where, in either of the above cases, fire fighting from within a small compartment is impracticable due to limitations in space, the hydrants required may be situated outside and ad-jacent to the compartment entrance.

3. The fire hoses are to be sufficient in length to protect a jet of water to any of the spaces in which they may be required to be used. The hoses are not to exceed 18 meters in length with a nozzle in size of 12 mm or over.

7303. International shore connectionIt is recommended that the top deck of the dock is provided with the international shore connection specified in Ch. II-2/Reg.19 of '74 SOLAS 1988 amend to supply water to the docking ship's ex-tinguisher from the dock's pump.

Ch 7 Fire Protection and Extinguishing Ch 7


7304. Portable extinguisher1. Portable extinguishers are to be placed onboard in places with risk of fire. Within the accom-

modation portable extinguishers are to be so placed that at least one extinguisher will be accessible from any part of the accommodation. The total number of extinguishers required within the accom-modation area will depend on its size and arrangement.

2. Portable extinguishers are to be provided in machinery spaces as well as spaces with electric mo-tors and switchboards etc. for pumps, warping capstans etc. Number and location will depend on the size and arrangement of the spaces.

7305. Fire smothering gas systemWhere provision is made for the injection of gas into machinery spaces for fire-extinguishing pur-poses, the necessary pipes for conveying the gas are to be provided with control valves or cocks which are to be so placed that they wi1l be easily accessible and not readily cut off from use by an outbreak of fire. Suitable provision is to be made to prevent inadvertent admission of the gas to any compartment.

2020

Guidance Relating tothe Rules for the Classification of

Floating Docks

GB-08-E KR

APPLICATION OF THE GUIDANCE

This "Guidances relating to the Rules for the Classification of Floating Docks" (hereafter called as the Guidance) is prepared with the intent of giving guidelines as to the treatment of the various provisions for items required the unified interpretations and items not specified in details in the Rules, and the requirements speci-fied in the Guidance are to be applied, in principle, in addition to the various provisions in the Rules.As to any technical modifications which can be regarded as equiv-alent to any requirements in the Guidance, their flexible application will be properly considered.

- i -

APPLICATION OF "GUIDANCES RELATING TO THE RULES FOR THE CLASSIFICATION OF

FLOATING DOCKS"

1. Unless expressly specified otherwise, the requirements in the Guidance apply to Floating Docks for which contracts for construction are signed on or after 1 July 2015.

2. The amendments to the Guidance for 2015 edition and their effective date are as fol-lows;

Effective Date 1 July 2015

Chapter 4 FREEBOARD AND STABILITY

4200. Stability- 4200. has been revised.

- iii -

CONTENTS

CHAPTER 1 GENERAL ··········································································································· 11100. General ···················································································································· 11101. Application ·············································································································· 1

CHAPTER 4 FREEBOARD AND STABILITY ······································································· 34200. Stability ····················································································································· 3

ANNEX GUIDANCE FOR DOCK GATES ··········································································· 51. General ···························································································································· 5

1.1 Application ············································································································· 51.2 Character of Classification ··················································································· 51.3 Plans and Documents to be submitted ························································· 5

2. Classification Surveys ··································································································· 52.1 Classification Surveys during Construction ······················································· 52.2 Periodical Survey ·································································································· 6

3. Stability ·························································································································· 63.1 Criteria of Stability Calculation ········································································ 63.2 Metacentric Height, ··························································································· 63.3 Stability Information ····························································································· 7

4. Structure and Strength ······························································································ 74.1 General ··················································································································· 74.2 Overall Strength ································································································· 74.3 Local Strength ········································································································ 84.4 Consideration for Deflection and Leakage ····················································· 11

5. Opening and Closing Equipment of Dock Gate ·················································· 115.1 Opening and Closing Equipment of Dock Gate ··········································· 115.2 Piping Systems ···································································································· 115.3 Electric Equipment ···························································································· 11

Ch 1 General Ch 1

Guidances Relating to the Rules for the Classification of Floating Docks 2020 1

CHAPTER 1 GENERAL

1100. General

1101. Application Dock gates not specified in 1101. of the Rules for Floating Docks are to be in accordance with the relevant requirements in Annex of the Guidance for Dock Gates.



CHAPTER 4 FREEBOARD AND STABILITY

4200. StabilitySemi-submersible heavy lift carriers engaged in international voyage may be in accordance with the followings.

1. Stability requirements in transit condition(1) 2008 IS Code Part A, Ch.2.2 and 2.3 apply. The windage area in loading conditions shall include

deck cargo.(2) If the vessel's characteristics render compliance with 2008 IS Code Part A, Ch. 2.2 impracticable,

then the criteria of Part B, Ch.2.4.5 may be used.(3) For intact stability the buoyancy provided by a part of large deck cargo such as semi-sub-

mersible units, jack-up units, barges or ships may be taken into account, provided that the se-curing arrangement is separately approved. The watertight integrity of the cargo is to be defined and taken into account in the calculations. And the application of this requirement shall be au-thorized by Administration.

(4) The damage stability standard shall be in accordance with SOLAS Ch.II-1 or ICLL 1966 Reg.27, including IACS UI LL65, as applicable.

(5) Ships with B reduced freeboard: B-60 freeboard requires one-compartment damage, while B-100 requires two-compartment

damage in accordance with Reg.27 of the ICLL 1966. The calculations are to be carried out as-suming the damaged tanks empty and for representative loads, such as a semi-submersible unit and a jack-up unit, as far as applicable. Damage extent is to be taken according to ICLL Reg. 27. The buoyancy of the deck cargo not located within the damage extent for each damage case may be taken into account if authorized by Administration. In all cases, transverse extent of damage shall be taken from the ship’s side. And the SOLAS limit curve is considered in addition as ships intended for the carriage of the deck cargo.

(6) Ships with B freeboard: If, in addition to the SOLAS limit curves, it is desired to take the buoyancy of the deck cargo

into account, calculations as for ICLL Reg. 27 corresponding to B-60 damage may be considered equivalent. And the application of this requirement shall be authorized by Administration.

2. Intact stability criteria in temporarily semi-submerged conditions(1) The loading and unloading sequences are so planned that the stability is sufficient during all

phases of the sequence. The buoyancy provided by a part of large deck cargo such as semi-submersible units, jack-up units, barges or ships may be taken into account.

(2) The GM at equilibrium shall not be less than 0.3 m. The positive range of the GZ curve shall be minimum 15° in conjunction with a height of not less than 0.1 m within this range. The max-imum righting arm shall occur at an angle of heel not less than 7°. Unprotected openings shall not be immersed within this range. It may be required to calculate the stability about additional axis to determine the most onerous result.

(3) Whenever free liquid surface exists in a tank, the effect shall be considered. The calculations shall account for the real filling of the tanks, i.e., in particular the location of air pipes needs to be carefully considered. If the complete filling of the tanks is dependent on certain trim or heel during the submerging sequence this needs to be clearly stated in the stability manual.

3. Damage stability in temporarily semi-submerged conditions(1) The risks of accidental flooding of any one compartment on the ship shall be considered.

Damage to be considered is that which might occur following an uncontrolled movement of the deck cargo during loading or offloading leading to puncture of exposed surfaces

(2) Accidental flooding of watertight compartment with watertight openings shall be considered in addition if this would result in a more severe condition.

(3) The permeability of a damaged compartment shall be assumed to be 0.95. For machinery spaces, a permeability = 0.85.

(4) In the final stage of flooding after damage, the positive range of the GZ curve shall be minimum 7° in conjunction with a height of not less than 0.05 m within this range. Unprotected openings shall not be immersed within this range unless the space concerned is assumed to be flooded. The angle of heel after flooding shall not exceed 15°. The final waterline after flooding is to be below the lower edge of any weathertight opening through which progressive flooding may take


4 Guidances Relating to the Rules for the Classification of Floating Docks 2020

place unless the space concerned is assumed to be flooded. It may be required to calculate the stability about additional axis to determine the most onerous result.

(5) The stability at intermediate stages of flooding after damage shall not be significantly less than in the final stage.

(6) The flooding of any damaged compartment shall not render vital safety functions inoperative.(7) For the purpose of damage stability calculations, a damage extent of 5 m horizontally along the

surface shall be assumed for all exposed surfaces except the cargo deck. Watertight bulkheads may be considered to remain intact provided that the distance between adjacent bulkheads ex-ceeds 5 m. The damage penetration into the structure shall be assumed to be equal to 0.76 m and the vertical extent of damage is assumed to be from the cargo deck or its horizontal ex-tension upwards without limit. For the cargo deck a damage extent of 5 × 5 m shall be assumed. Watertight bulkheads may be considered to remain intact provided that the distance between adjacent bulkheads exceeds 5 m. The damage penetration into the cargo deck shall be assumed to be equal to 0.76 m.

ANNEX


ANNEX GUIDANCE FOR DOCK GATES

1. General

1.1 Application (1) This Guidance applies to the dock gates which are intended to be classed with the Society.(2) Items not specified in this Guidance are to be in accordance with the relevant parts of the

Rules for the Classification of Steel Ships and the Rules for Floating Docks, as far as applicable.

1.2 Character of ClassificationThe class notations assigned to the dock gate classed with the Society are to be in accordance with the requirements specified in Pt 1, Ch 1, 201. of the Rules. However, the notation "Dock Gate" shall be assigned as a ship type notation.

1.3 Plans and Documents to be submitted(1) Plans for approval

(A) Transverse section scantlings at mid-length of dock(B) Structural plans of the wing walls, decks and bulkheads(C) Structural plans of the transverse section (D) Piping diagram(E) Details of sea chest and ship-side distance pieces

(2) Plans and Documents for Information(A) Specifications(B) General arrangement plan(C) Tank arrangements (D) Calculation sheets and data for overall strength and local strength (E) Operating manual including stability information (F) Coating specifications(G) Arrangements and details of seals

2. Classification Surveys

2.1 Classification Surveys during Construction(1) Survey

For classification survey of a dock gate, the materials, workmanship and arrangements are to be surveyed in the presence of the Surveyor from the commencement of the work until the com-pletion of the dock, and until the completion of the final test for machinery under the working condition. Any item found not to be in accordance with the Rules or the approved plans, or any material, workmanship or arrangement found to be unsatisfactory are to be rectified.

(2) Hydraulic testHydraulic test and leak test are to be carried out in accordance with Pt 3, Ch 1, 209. of the Rules in the presence of the Surveyor.

(3) Inclining test(A) The inclining test is to be carried out under the work completion state as par as practicable

in order to obtain correct light displacement and the position of the center of gravity of the dock gate.

(B) Prior to the inclining test, inclining testing schemes are to be submitted to the Society, and inclining test is to be carried out in the presence of the Surveyor.

(4) Opening and closing test of dock gate After the completion of dock gate, opening and closing test of dock gate is to be carried out in accordance with operation manual and the condition is to be confirmed and leakage of water is to be checked. In this case, quantity of leakage is not to exceed a half of the capacity of drain-

ANNEX


age system of the shipbuilding dock. 2.2 Periodical Survey

(1) Intermediate Surveys(A) Intermediate Survey is to be carried out within 3 months before or after the second or the

third anniversary date from the completion date of the initial classification survey or of the previous Special Survey.

(B) Intermediate Survey is to be carried out under the condition that dock gate is lifted to mini-mum draft.

(C) At each Intermediate Survey, the following parts are to be examined.(i) The shell plating above the waterline.(ii) Internal examination of representative compartment.(iii) Condition of air pipes, overflow pipes and overboard scuppers.(iv) Companionways, ladders, and handrails and other means of protection that might be

provided for access to all spaces.(v) Condition of machinery, pumps and emergency lifting equipment.(vi) Condition of seals above water line.

(2) Special Survey(A) The first Special Survey is to be completed within 5 years from the date of initial

classification survey and thereafter within 5 years from the credited date of the previous Special Survey.

(B) Special Survey of dock gate is to be carried out under the condition of dry docking or on slipway. However, the Survey of the outer bottom below the light waterline, at the Special Survey, may be carried out by some combination of the following methods. (i) Ultrasonic measurement of plate thickness.(ii) Heeling of the dock for partial examination of the bottom.(iii) Underwater photography.(iv) Underwater television.(v) Examination by diver.

(C) For each Special Survey, following requirements are to be examined in addition to the Intermediate Survey requirements. (i) Condition of means of protection to openings (ii) Internal examination of all compartments. However, internal examination of fresh water

tank may be omitted where the result of outer inspection is good. (iii) From the third Special Survey, the thicknesses measurement for the structural members

is to be carried out. Two transverse sections within the 0.4 mid-length of the dock gate are to be measured.

(iv) Wear-down condition of seals

3. Stability

3.1 Criteria of Stability Calculation (1) Stability calculation is to be in accordance with following conditions.

(A) The position of center of gravity of dock gate is to be obtained from the results of inclining test.

(B) The free surface effect of liquid tanks is to be considered. (2) Further details other than above, Pt 1, Annex 1-2 of Guidance relating to the Rules is to be ap-

plied to stability calculation.

3.2 Metacentric Height,

The initial metacentric height is not to be less than 1.0 m for the each following condition. (1) Lifted condition with minimum draft(2) Each lifted condition taking into account the tidal difference

ANNEX


3.3 Stability Information

Stability Information is to include following. (1) Capacity and the location of center of compartments and tanks, and the moment of inertia of

free surface to be presented in numerical tables or curves(2) Hydrostatic curves or numerical tables(3) Other data deemed necessary by the Society.

4. Structure and Strength

4.1 General

The dock gate is to have adequate strength and stiffness fit for the environmental condition and operational condition of water area in service.

4.2 Overall Strength (1) Overall Strength of the dock gate is to be assessed by direct strength calculation method in ac-

cordance with the following.(2) Analysis method

(A) The Analysis methods and programs are to be capable of taking the effects of bending de-formation, shear deformation, axial deformation, and warping deformation into account.

(B) The analysis methods and programs are to be such that the behaviors of plane or space structures can be effectively expressed and displayed under the reasonable boundary condition.

(C) The analysis program is to have a sufficient analysis accuracy. And if deemed necessary by the Society, the Society may require the submission of the data on the details of analysis method, verification of accuracy, etc.

(D) Where direct strength calculation is performed, documents describing the conditions of calcu-lation and the data summarizing their results are to be submitted to the Society.

(3) Load (A) The design loads for the dock gate are to be such that the most severe load conditions tak-

ing into account of the environment of water area in service are considered.(B) The design loads are to be presented by the builder and to be specified in the drawings and

documents for approval.(C) Where vehicles pass over the dock gate, the vehicle loads are to be considered and not to

be less than 17.2 kN/m2. (4) Structural model

(A) Structural modelling for analysis is to be in accordance with Pt 3, Annex 3-2 of Guidance Relating to the Rules.

(B) However, structural modelling is to be carried out based on the net thickness excluding thicknesses for corrosion margin.

(5) Allowable stress (A) When structure analysis is carried out by overall model of steel-made dock gate, allowable

stress is to be in accordance with the following:(i) Allowable stress when plate elements are used.

Normal stress : (N/mm2)Shear stress : (N/mm2)Equivalent stress : (N/mm2) : in accordance with the following formula:

(N/mm2)

ANNEX


: material factor of used material as follows: A, B, D and E : 1.0AH 32, DH 32 and EH 32 : 0.78AH 36, DH 36 and EH 36 : 0.72AH 40, DH 40 and EH 40 : 0.68

(ii) Allowable stress when beam elements are used;

Web of beam elements : equivalent stress (N/mm2)

shear stress (N/mm2)Flange of beam elements : longitudinal stress of dock gate (N/mm2) transverse stress of dock gate (N/mm2)Equivalent stress is to be in accordance with the following:

(N/mm2)

: in-plane normal stress, to be in accordance with the following:

: axial stress : bending stress : mean shear stress

(iii) Where deemed necessary by the Society, fine mesh analysis may be required. In this case, the allowable stress is to be deemed appropriate by the Society.

(B) Allowable stress of dock gate made of special material other than steel is to be deemed appropriate by the Society.

4.3 Local Strength

Structural members used for deep tank are to comply with the following, in addition to the require-ments of 4.2. as above.

(1) Bulkhead plate of deep tankThe thickness(t) of the bulkhead plate of deep tank is not to be less than that obtained from the following formula;

(mm) where, : spacing of bulkhead stiffeners (mm) : the greater of the following

(A) vertical distance measured from the lower edge of each bulkhead plate to the mid-point of the distance between the top of tanks and the top of overflow pipes.(m)

ANNEX


(B) 0.7 times the distance measured from the lower edge of each bulkhead plate to the point of 2.0 m above the top of overflow pipes(m)

(2) Bulkhead stiffeners of deep tankThe section modulus () of bulkhead stiffeners of deep tank is not to be less than that obtained from the following formula;

(cm3)

where, : as specified in (1). : span of the bulkhead stiffeners in meters : vertical distance given below, whichever is the greater, the lower end being

regarded as the midpoint of for vertical stiffeners and as the midpoint of distance between the adjacent stiffeners for horizontal stiffeners.

(A) vertical distance measured from the lower end to the midpoint of the dis-tance between the top of tanks and the top of overflow pipes(m)

(B) 0.7 times the vertical distance measured from the lower end to the point of 2.0 m above the top of overflow pipes

: Coefficient given in following Table, according to the type of end connections

One end of stiffeners

The other end of stiffeners

Rigid connection by brackets

Flexible connection by brackets

Lug-connection or

supported by girders

Snip

Rigid connection by brackets 4.90 8.05 5.95 9.10

Flexible connection by brackets 8.05 5.95 9.10 8.05

Lug-connection or supported by girders 5.95 9.10 7.00 10.50

Snip 9.10 8.05 10.50 10.50

Values of

(3) Strengthening girder(A) The section modulus () of the strengthening girders(hereinafter referred to as girder) sup-

porting stiffeners is not to be less than that obtained from the following formula;

(cm3)

where : : breadth of the area supported by the girders in meters : vertical distance measured from the mid-point of for horizontal girders, and

from the midpoint of for vertical girders, to the top of specified in (2) in meters

: span of the girders in meters(B) The moment of inertia () of girders is not to be less than that obtained from the following

formula. However, the dept of girders is not to be less than 2.5 times the dept of slots for stiffeners.

ANNEX


(cm4)

where, and : as specified in the preceding paragraph (A)

(C) Thickness of the girder web is not to be less than that obtained from the following three formulas, whichever is the greatest.

(mm)

(mm)

(mm)

where, , and : as specified in the preceding paragraph (A) : spacing of web stiffeners or the depth of girders, whichever is the smaller

(mm) : depth of the girder at the location considered, reduced by the depth of slots

for stiffeners (mm) : Coefficient obtained from the following three formulas. However, it is not to

be less than 0.5.

For horizontal girders :

For vertical girders :

: Distance measured from the end of for horizontal girders, and from the low-er end of for vertical girders, to the location considered (m)

(D) The actual section modulus and moment of inertia of girders are to be calculated in accord-ance with Pt 3, Ch 1, 602. of the Rules.

(4) Cross Ties(A) Where efficient cross ties are provided across deep tanks connecting girders on each side of

the tanks, the span( ) of girders specified in (3) may be measured between the end of gird-er and the center line of cross tie or between the centerlines of adjacent cross ties.

(B) The sectional area(A) of cross ties is not to be less than that obtained from the following formula.

(cm2)

where : and : As specified in (3) : Breadth of the area supported by cross ties(m)

(C) The ends of cross ties are to be bracketed to girders.(5) Top and bottom construction

The scantlings of the members forming the top or the bottom of deep tanks are to be in ac-cordance with the requirements of 4. of this Annex, regarding the members as the members forming the deep tank bulkheads at the location. For top plating of deep tanks, the thickness of plates is to be at least 1 mm greater than that specified in (1) above.

ANNEX


(6) Scantlings of members not in contact with sea waterThe thickness of bulkhead plates and girders which are not in contact with sea water in service conditions may be reduced from the requirements in (1), (3) and (4) by the values given below:

For the plates of which only one side is in contact with sea water ------ 0.5 mmFor the plates of which neither side is in contact with sea water -------- 1.0 mm

However, bulkhead plate in way of the location such as bilge wells are to be regarded as plates in contact with sea water.

(7) All structural members are to be sufficiently considered in respect of buckling. 4.4 Consideration for Deflection and Leakage

(1) The structural scantlings of the dock gate are to be determined taking into account negative(-) deflection(in the reverse direction against that of loading) due to reaction forces at longitudinal ends of the dock gate. the calculation results of negative(-) deflection at longitudinal ends are to be submitted to the Society.

(2) Seals are to be provided along the longitudinal ends and bottom of dock gate to prevent leakage. Details for the seal structure and its material property including compressive strength are to be submitted to the Society.

(3) Pump and drainage system are to be provided in dock gate to discharge sea water leaking from the dock gate into the dock.

5. Opening and Closing Equipment of Dock Gate

5.1 Opening and Closing Equipment of Dock Gate(1) Appropriate equipment is to be provided for opening and closing the dock gate.(2) The type of lifting and immersion for opening and closing the dock gate may be of pumping or

valve operation using gravity. (3) Where equipment such as pneumatic pressure is used as emergency drainage system and it

may affect the design of dock gate, documents for verification of safe operation of this system are to be submitted to the Society by maker. If necessary, the Society may require additional safety devices.

5.2 Piping Systems

Auxiliaries and piping systems of the dock gate are to be designed, manufactured and installed in accordance with Pt 5 of the Rules as par as applicable.

5.3 Electric Equipment

Electric equipment of the dock gate is to be designed, manufactured and installed so that electrical impact, fire and other electrical hazard are to be avoided, in accordance with Pt 6 of the Rules as par as applicable.

RULES AND GUIDANCES RELATING TO RULES FOR THE CLASSIFICATION OF

FLOATING DOCKS

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Rules and Guidance for the Classification of Floating Docks

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